JP2012147366A - Communication system and mobility anchor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform application even outside a range of a standard sequence using PMIPv6 for an I/F between S-GW and P-GW without adding a function to a policy server and without raising loads.SOLUTION: The policy server transmits an additional bearer setting request for associating a communication path of a first terminal and a communication path of a second terminal to a mobility anchor. In the case of receiving the additional bearer setting request, the mobility anchor determines the propriety of setting a fifth communication path connecting a first communication path and a third communication path, records information related to the fifth communication path about the propriety of setting the fifth communication path in communication path management information, and transmits a link preparation request including the communication path management information to an access gateway device. The access gateway device transmits data transmitted from the first terminal through the first communication path to the second terminal through the fifth communication path and the third communication path.

Description

  The present invention relates to a communication system and a mobility anchor, and more particularly to a communication system and a mobility anchor that return user traffic within an access gateway when users accommodated in the same or neighboring access gateway communicate with each other.

  In a 3.9th generation mobile communication network represented by LTE (Long Term Evolution) of 3GPP (3rd Generation Partnership Project), the network is all IP. For this reason, the telephone service conventionally provided by the circuit switching network is realized on the IP network.

  The LTE IP network includes an access network and an access-independent service network. An LTE access network includes a base station (eNB (evolutional Node B)) that performs radio communication, an MME (Mobility Management Entity) that manages terminal location and connection control, and an S-GW (Serving) that distributes user traffic to a service network. Gateway) and a P-GW (Packet data network Gateway) that forwards traffic from the S-GW to the service network and collects billing data.

  On the other hand, the LTE access-independent service network is a call control network called IMS (IP Multimedia Subsystem) in the case of telephone service. In IMS, a SIP (Session Initiation Protocol) server called CSCF (Call Session Control Function) associates a telephone number with the IP address of a terminal and manages a call session. The P-GW that connects the LTE access network to the IMS transfers call control signals from the terminals to the CSCF and voice signals between the terminals, and collects accounting data (number of transfer packets, transfer data amount, etc.). It has a function.

The MME and S-GW of the LTE access network are installed in a location close to the base station for tying up with the base station. On the other hand, the P-GW connecting the LTE access network and the IMS is installed on the core network side close to the service network in order to be tied to the service network. Therefore, particularly when the terminals are accommodated in the same S-GW, there is a problem that a transfer delay occurs due to the transfer of voice traffic to the IMS P-GW and the bandwidth of the core network is compressed.
As a method of transferring voice traffic without going through the P-GW, “Proxy Mobile IPv6 Route” is a method of directly establishing a data path between Mobile Access Gateways (which correspond to S-GW in LTE) accommodating terminals. Optimization "(see Non-Patent Document 1). However, Non-Patent Document 1 stipulates a method for setting a data path for Proxy Mobile IPv6 Route Optimization, but does not mention a setting trigger or a method for determining a setting target.

  Patent Document 1 discloses a communication system and an access gateway device that can optimize a route without losing charging information without passing through a P-GW (mobility anchor). Here, the mobility anchor is a superordinate concept of the P-GW.

JP 2010-088013 A

IETF draft-qin-netlmm-pmipro-00 PMIPv6 Route Optimization

  However, in Patent Document 1, the policy server determines route control in order to transmit a link creation request. The load on the policy server increases due to the determination that is not performed. Since the policy server generally has a larger number of subscribers per unit than other nodes, the load tends to increase.

  Patent Document 1 is not applicable except for a standard sequence range using PMIPv6 (Proxy Mobile Internet Protocol Version 6) for the I / F between the S-GW and the P-GW.

  In the communication system including a mobility anchor that connects a terminal to a packet data network, an access gateway apparatus that connects the terminal to the mobility anchor, and a policy server that controls the mobility anchor and the access gateway apparatus, Includes a first access gateway device, a first communication path is set between the first terminal and the first access gateway device, and a second is set between the first access gateway device and the mobility anchor. Communication path is set, a third communication path is set between the second terminal and the first access gateway apparatus, and a fourth communication path is set between the first access gateway apparatus and the mobility anchor. And the first terminal is connected to the first communication path, the second communication path, and the fourth communication path. The mobility anchor communicates with the second terminal via the third communication path, the mobility anchor manages communication path management information including information on the communication path of each terminal, and the policy server transmits the communication path of the first terminal. , And an additional bearer setting request for associating the communication path of the second terminal to the mobility anchor. When the mobility anchor receives the additional bearer setting request, the mobility anchor first analyzes the contents of the additional bearer setting request. To determine whether it is possible to set the fifth communication path to be connected to the third communication path and the third communication path, and to determine whether the fifth communication path is to be set. The information is recorded, and a link creation request including the communication path management information is transmitted to the first access gateway apparatus. The first access gateway apparatus receives the first information from the first terminal based on the communication path management information. The transmitted via the communication channel data, the fifth communication path, and the third communication system to be transmitted to the second terminal via the communication path can be achieved.

  A mobility anchor in a communication system comprising: a mobility anchor that connects a terminal to a packet data network; an access gateway device that connects the terminal to the mobility anchor; and a policy server that controls the mobility anchor and the access gateway device. The gateway device includes a first access gateway device, a first communication path is set between the first terminal and the first access gateway device, and between the first access gateway device and the mobility anchor. A second communication path is set, a third communication path is set between the second terminal and the first access gateway apparatus, and a fourth communication path is set between the first access gateway apparatus and the mobility anchor. The first terminal is connected to the first communication path, the second communication path The mobility anchor communicates with the second terminal via the communication path, the fourth communication path, and the third communication path, the mobility anchor manages communication path management information including information on the communication path of each terminal, and the policy server When the additional bearer setting request for associating the first communication path and the third communication path is transmitted to the mobility anchor, and the mobility anchor receives the additional bearer setting request, the mobility anchor analyzes the content of the additional bearer setting request Thus, it is determined whether or not it is possible to set the fifth communication path that connects the first communication path and the third communication path, and whether or not the fifth communication path is set is determined as information on the fifth communication path. Can be achieved by a mobility anchor that records a link creation request including the communication path management information to the access gateway device.

  According to the present invention, the shortest data path can be set without increasing the load on the policy server and without depending on PMIPv6.

It is a figure explaining the structural example of a communication network. It is a block diagram explaining the apparatus structure of P-GW. It is a figure explaining the structure of the service information management table with which PCRF is provided. It is a figure explaining the structure of the bearer information management table with which PCRF is provided. It is a figure explaining the structure of the bearer information management table with which P-GW after a path | route determination is provided. It is a flowchart figure explaining the route determination which P-GW implements. It is the sequence diagram (the 1) explaining the session establishment call flow in case two UEs are accommodated in the same S-GW. It is a sequence diagram (the 2) explaining the session establishment call flow in case two UEs are accommodated in the same S-GW. It is a figure explaining the structural example of a communication network. It is a figure explaining the structure of the bearer information management table with which PCRF is provided. It is a figure explaining the structure of the bearer information management table with which P-GW after a path | route determination is provided. It is a flowchart figure explaining the route determination which P-GW implements. It is the sequence diagram (the 1) explaining the session establishment call flow in case two UEs are accommodated in different S-GWs. It is a sequence diagram (the 2) explaining the session establishment call flow in case two UEs are accommodated in different S-GWs. It is a sequence diagram (the 3) explaining the session establishment call flow in case two UEs are accommodated in different S-GWs.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings using examples. The same reference numerals are assigned to substantially the same parts, and the description will not be repeated. In addition, although the embodiments described below describe 3GPP LTE, the present invention is not limited to this, and can be applied to various wireless communication systems such as WiMAX or WLAN.

  Hereinafter, a process when a UE (User Equipment) 71 and a UE 72 are accommodated in the same S-GW 42 will be described with reference to FIGS. 1 to 7. First, the configuration of the communication network will be described with reference to FIG. In FIG. 1, a communication network 1000 includes a PDN network 1, an IMS network 2, an LTE core network 3, a CSCF 11, a PCRF (Policy and Charging Rules Function) 12, a P-GW 21, an HSS (Home Subscriber Server) 22, an MME 41, 42, S-GW42, 52, eNB43A-43C, eNB53A-53C are provided.

  UE71 and UE72 are user terminals provided with a wireless communication function. UE71 and UE72 are connected to a network of a communication carrier via eNB43 (43A-43C).

  The network of the telecommunications carrier is composed of eNBs 43A to 43C and eNBs 53A to 53C constructed in units of areas such as prefectures, and PDN networks 1, eNBs 43A to 43C, eNBs 53A to 53C, and PDN networks 1 that aggregate regional networks nationwide. The network includes an LTE core network 3 that connects them, and an IMS network 2 that is installed in each service unit.

  The network of the communication carrier is connected to an eNB 43 (43A to 43C) that performs wireless communication with the terminal, an MME 41 that performs terminal mobility management and connection control, and an S-GW 42 that distributes user traffic from the terminal to the service network. The same applies to the eNB 53 (53A to 53C). In addition, when not distinguishing in particular, eNB43 (43A-43C) and eNB53 (53A-53C) are described as eNB43 and 53.

  An HSS 22 that manages user authentication information and a P-GW 21 that transfers user traffic to the IMS network 2 are connected to the LTE core network 3.

  In this embodiment, the IMS network 2 controls telephone calls. The IMS network 2 is connected to a call control server (CSCF) 11 and a policy server (PCRF) 12 that controls the P-GW 21 and the S-GWs 42 and 52 based on service information transmitted from the CSCF 11.

  Conventionally, audio data transmitted from the UE 71 has been transmitted to the UE 72 via a path indicated by a broken line. That is, the conventional audio data path always passes through the P-GW 21.

  In the first embodiment, the audio data path becomes a path as shown by a solid line by a process described later (described later with reference to FIG. 7). That is, the audio data is returned and transmitted within the S-GW 42 without passing through the P-GW 21.

  The apparatus configuration of the P-GW 21 will be described with reference to FIG. In FIG. 2, the P-GW 21 includes a hard disk 101, a CPU 102, a RAM 103, and IFs 104A and 104B. These are connected to each other via a bus 105.

  A program for realizing the function of the P-GW 21 is stored in the Hard Disk 101. The program is expanded in the RAM 103 when the P-GW 21 is activated. The CPU 102 executes a program expanded in the RAM 103.

  The configuration of the service information management table 150 provided in the PCRF 12 will be described with reference to FIG. In FIG. 3, the service information management table 150 manages service information transmitted from the CSCF 11. The service information is information indicating what kind of communication the voice data is transmitted between terminals. In addition to the audio data, information on other services is also included.

  The service information management table 150 includes a service session ID 151 and flow information 152. The service session ID 151 stores an identifier that uniquely identifies the service session. The flow information 152 includes a flow ID 152A, a flow filter 152B, a media type 152C, and a band 152D as information on flows belonging to the service session.

The flow ID 152A stores an identifier that uniquely identifies the flow. The flow filter 152B stores information for specifying a flow. Specifically, the IP address and port number of the node with which communication is performed are stored. The media type 152C stores the media type of the flow. For example, when the media type 152C is “audio”, it indicates voice communication. The band 152D stores a value indicating the band used by the flow. Specifically, the amount of transmission data per second is stored.
In FIG. 3, an entry 150A and an entry 150B are created in the flow information 152.

  The structure of the bearer information management table 170 provided in the PCRF 12 will be described with reference to FIG. 4, the bearer information management table 170 manages bearer information transmitted from the P-GW 21 and the S-GWs 42 and 52. The bearer information is information related to the bearer used for transferring the service flow.

  The bearer information management table 170 includes a user ID 171, a user IP 172, a P-GW ID 173, an S-GW ID 174, and bearer information 175. The user ID 171 stores an identifier for uniquely identifying the terminal. “User # 1” is assigned as the user ID 171 of the UE 71 in FIG. On the other hand, “user # 2” is assigned to the user ID 171 of the UE 72.

  User IP 172 stores the IP address assigned to the terminal. The user IP of the UE 71 in FIG. 1 is assigned “192.168.0.0.100”. On the other hand, the user IP 172 of the UE 72 is assigned “192.168.0.200”.

  The P-GW ID 173 stores an IP address assigned to the P-GW 21 through which voice data is transferred. The S-GW ID 174 stores the IP address assigned to the S-GWs 42 and 52 through which the voice data is transferred.

  The bearer information 175 stores information on bearers set in the S-GWs 42 and 52 and the P-GW 21. Specifically, the bearer information 175 includes a flow ID 175A, an intra-P-GW bearer ID 175B, and an intra-S-GW bearer ID 175C.

  The flow ID 175A stores an identifier for identifying a flow transferred using the set bearer. This is the same as the flow ID 152A. The intra-P-GW bearer ID 175B stores an identifier for identifying the bearer set in the P-GW 21. The intra-P-GW bearer ID 175B is an identifier assigned by the P-GW 21. The intra-S-GW bearer ID 175C stores an identifier for identifying the bearer set in the S-GWs 42 and 52. The intra-S-GW bearer ID 175C is an identifier assigned by the S-GWs 42 and 52.

  In FIG. 4, entries 170A and 170B are created in the bearer information 175. Both the entry 170A and the entry 170B are assigned the IP address of the S-GW 42.

  Conventionally, since voice data or the like is transferred via the P-GW 21, the intra-P-GW bearer ID 175B is always set information. However, in the first embodiment, audio data or the like is transferred without going through the P-GW 21 by a process described later.

  With reference to FIG. 5, the bearer information management table 180 with which P-GW21 is provided is demonstrated. In FIG. 5, the bearer information management table 180 determines the return at the same S-GW in the P-GW 21 based on the information in the bearer information management table 170 included in the PCRF 12 in FIG. 4 (described later with reference to FIG. 6). Manage the information if The bearer information is information related to the bearer used for transferring the service flow.

  In FIG. 5, the bearer information management table 180 includes a user ID 181, a user IP 182, a P-GW ID 183, an S-GW ID 184, and bearer information 185. The user ID 181 stores an identifier for uniquely identifying the terminal. “User # 1” is assigned to the user ID 181 of the UE 71 in FIG. On the other hand, “user # 2” is assigned to the user ID 181 of the UE 72. User IP 182 stores the IP address assigned to the terminal. The user IP of the UE 71 is assigned “192.1688.0.100”. On the other hand, the user IP 182 of the UE 72 is assigned “192.168.0.200”.

  The P-GW ID 183 stores an IP address assigned to the P-GW 21 through which voice data is transferred. The S-GW ID 184 stores the IP address assigned to the S-GWs 42 and 52 through which the voice data is transferred.

  The bearer information 185 is determined based on information on route determination (described later with reference to FIG. 7). The bearer information 185 stores information on bearers set in the S-GWs 42 and 52 and the P-GW 21. Specifically, the bearer information 185 includes a flow ID 185A, an intra-P-GW bearer ID 185B, and an intra-S-GW bearer ID 185C.

  The flow ID 185A stores an identifier for identifying a flow transferred using the set bearer. The flow ID 185A is the same as the flow ID 152A. The intra-P-GW bearer ID 185B stores an identifier for identifying a bearer set in the P-GW 21. The intra-P-GW bearer ID 185B is an identifier assigned by the P-GW 21. The intra-S-GW bearer ID 185C stores an identifier for identifying a bearer set in the S-GWs 42 and 52. The intra-S-GW bearer ID 185C is an identifier assigned by the P-GW 21.

  In FIG. 5, entries 180A and 180B are created in the bearer information 185. In the bearer management information 170 of FIG. 4, the IP address of the P-GW 21 and the IP address of the S-GW 42 are assigned to both the entries 170A and 170B. For this reason, “-” is set in the identifier for identifying the bearer set in the P-GW 21 in the bearer ID 185B in the P-GW of the bearer information 185. For the intra-S-GW bearer ID 185C, the intra-S-GW bearer ID “5101” including “user # 2 (UE 72)” of the user ID 181 of the communication partner and the intra-S-GW bearer ID “5201” is set in the entry 180A. The On the other hand, the intra-S-GW bearer ID “5201” including the “user # 1 (UE 71)” of the user ID 181 of the communication partner and the intra-S-GW bearer ID “5101” is set in the entry 180B. Note that when “-” is set in the identifier of the intra-P-GW bearer ID 185B, no bearer is added to the P-GW.

  With reference to FIG. 6, the flow of the route determination of the P-GW 21 will be described. In FIG. 6, this flow is started when waiting for an additional bearer setting request from the PCRF. The P-GW 21 waits for reception of an additional bearer setting request from the PCRF (S101: NO). When an additional bearer setting request is received from the PCRF (S101: YES), the P-GW 21 acquires user information included in the additional bearer setting request (S102). The P-GW 21 determines whether a plurality of UEs are accommodated in the same P-GW based on the information in the bearer information table 170 (S103). When YES, the P-GW 21 determines whether two UEs are accommodated in the same S-GW (S104). When YES, the P-GW 21 determines a return within the same S-GW (S106) and ends the route determination. When step 103 or step 104 is NO, the P-GW 21 ends the route determination as it is.

  With reference to FIG. 7, the session establishment call flow when two UEs are accommodated in the same S-GW will be described. In FIG. 7A, first, the UE 71 is connected to the P-GW 21 via the eNB 43C, the MME 41, and the S-GW 42, and a general-purpose bearer is established. Moreover, UE72 is connected to P-GW21 via eNB43A, MME41, and S-GW42, and is in the state in which the general-purpose bearer was established. At this time, the IP address “192.168.0.0.100” is assigned to the UE 71. On the other hand, the IP address “192.168.0.200” is assigned to the UE 72. Also, the bearer information management table 170 managed by the PCRF 12 is in a state in which entries 170A and entries 170B related to the general-purpose bearer are set.

  Next, a call session is negotiated between the UE 71 and the UE 72 using SIP (S401). A circle on the line is a member participating in the call session. The CSCF 11 extracts service information (communication IP address of voice traffic, port number, media type, used bandwidth, etc.) from the SIP message transmitted / received between the UE 71 and the UE 72, and transmits the extracted service information to the PCRF 12. (S402). The PCRF 12 sets the transmitted information in the service information management table 150, and returns an ACK to the CSCF 11 (S403). 150A and 150B in FIG. 3 show settings when UE 71 and UE 72 negotiate bidirectional voice communication.

  Next, the PCRF 12 determines a policy relating to bearer establishment based on the transmitted service information (S404). The PCRF 12 that has determined the policy regarding bearer establishment in Step 404 transmits an additional bearer setting request to the P-GW 21 (S406). The additional bearer setting request includes a user ID 171, a flow filter 152B, and QoS / billing information. The dedicated bearer setting request includes other information.

  The P-GW 21 that has received the additional bearer setting request performs route determination based on the information included in the received additional bearer setting request (S407). After the route determination, the P-GW 21 transmits an S-GW return bearer setting request to the S-GW 42 (S408). The S-GW loopback bearer setting request includes a bearer information table 180 and QoS / billing information. The S-GW loopback bearer setting request includes other information.

  The S-GW 42 that has received the S-GW return bearer setting request transmits a bearer establishment request to the MME 41 based on the information included in the received S-GW return bearer setting request, and between the UE 71 and the eNB 43C, and the eNB 43C. And an additional bearer are established between the S-GW 42 (S409).

  After the additional bearer is established in step 409, the S-GW 42 returns an S-GW return bearer setting response to the P-GW 21 (S411). The P-GW 21 that has received the S-GW loopback bearer setting response returns an additional bearer setting response to the PCRF 12 (S412). Next, the PCRF 12 transmits an additional bearer setting request to the P-GW 21 (S413).

  In FIG. 7B, the P-GW 21 that has received the additional bearer setting request transmits an S-GW return bearer setting request to the S-GW 42 that accommodates the UE 72 (S414).

  In steps 414 to 417, processing similar to that in steps 408 to 411 is performed. That is, in step 414, the S-GW 42 that has received the S-GW loopback bearer setting request transmits a bearer establishment request to the MME 41 based on the information included in the received S-GW loopback bearer setting request in step 416. The additional bearer is established between the UE 72 and the eNB 43A and between the eNB 43A and the S-GW 42. In step 417, the S-GW 42 returns an S-GW return bearer setting response to the P-GW 21.

  The P-GW 21 that has received the S-GW return bearer setting response returns an additional bearer setting response to the PCRF 12 (S418). Next, the PCRF 12 transmits an inter-bearer link creation request to the P-GW 21 (S419). In the inter-bearer link creation request, link source bearer information (information related to the bearer used for the UE 71 to transmit and receive voice data) and link destination bearer information (information related to the bearer used for the UE 72 to transmit and receive voice data) and It is included.

  The P-GW 21 that has received the inter-bearer link creation request transmits an inter-bearer link creation request to the S-GW 42 (S421). The S-GW 42 that has received the inter-bearer link creation request creates link information between the bearers based on the information included in the received inter-bearer link creation request (S422).

  The S-GW 42 that created the inter-bearer link in step 422 transmits a link creation notification to the MME 41 (S234). The link creation notification to be transmitted includes link information. The MME 41 that has received the link creation notification stores the link information included in the link creation notification and returns an ACK to the S-GW 42 (S424). Next, the S-GW 42 transmits a bearer link creation response to the P-GW 21 (S426).

  The P-GW 21 that has received the bearer link creation response transmits a bearer link creation response to the PCRF 12 (S427). The PCRF 12 that has received the bearer link creation response transmits a bearer setting completion notification to the CSCF 11 (S428). The CSCF 11 that has received the bearer setting completion notification returns an ACK to the PCRF 12 (S429). UE71 and UE72 complete the SIP session establishment between them (S431).

  Thereafter, voice communication between the UE 71 and the UE 72 is started, and the voice traffic is transferred through a route of [MN71-eNB43C-S-GW42-eNB43A-CN72].

  In the conventional communication system, the voice traffic is transferred through the route [MN71-eNB43C-S-GW42-eNB43A-CN72] by the QoS judgment routine of the PCRF 12, but in this embodiment, the route judgment is performed by the P-GW21. There is a feature.

  In the second embodiment, a route of voice traffic when UE 71 and UE 72 are accommodated in different S-GW 42 and S-GW 52 will be described. Hereinafter, the session establishment process when the UE 71 and the UE 72 are accommodated in different S-GWs 42 and S-GWs 52 will be described with reference to FIGS. First, the configuration of a communication network in the second embodiment will be described with reference to FIG. In FIG. 8, the UE 71 is accommodated in the S-GW 52. On the other hand, UE72 is accommodated in S-GW42.

  In the conventional communication system, voice traffic is transferred through a route of [UE71-eNB53A-S-GW52-P-GW21-S-GW42-eNB43A-UE72]. However, in the second embodiment, the voice traffic is transferred through the route [UE71-eNB53A-S-GW52-S-GW42-eNB43A-UE72] by the process described later.

  With reference to FIG. 9, the structure of the bearer information management table 190 with which PCRF12 is provided is demonstrated. 9, the bearer information management table 190 manages bearer information transmitted from the P-GW 21 and the S-GWs 42 and 52. The bearer information is information related to the bearer used for transferring the service flow. The bearer information management table 190 includes a user ID 191, a user IP 192, a P-GW ID 193, an S-GW ID 194, and bearer information 195.

  The user ID 191 stores an identifier for uniquely identifying the terminal. “User # 1” is assigned as the user ID 191 of the UE 71 in FIG. On the other hand, “user # 2” is assigned to the user ID 191 of the UE 72. The user IP 192 stores the IP address assigned to the terminal. The user IP of the UE 71 in FIG. 8 is assigned “192.168.0.0.100”. On the other hand, the user IP 192 of the UE 72 is assigned “192.168.0.200”.

  The P-GW ID 193 stores an IP address assigned to the P-GW 21 through which voice data is transferred. The S-GW ID 194 stores the IP address assigned to the S-GWs 42 and 52 through which the voice data is transferred.

  The bearer information 195 stores information on bearers set in the S-GWs 42 and 52 and the P-GW 21, and specifically includes a flow ID 195A, a P-GW bearer ID 195B, and an S-GW bearer ID 195C. The flow ID 195A stores an identifier for identifying a flow transferred using the set bearer. This is the same as the flow ID 152A. The intra-P-GW bearer ID 195B stores an identifier for identifying a bearer set in the P-GW 21. The intra-P-GW bearer ID 195B is an identifier assigned by the P-GW 21. The intra-S-GW bearer ID 195C stores an identifier for identifying the bearer set in the S-GWs 42 and 52. The intra-S-GW bearer ID 195C is an identifier assigned by the S-GWs 42 and 52.

  In FIG. 9, entries 190A to 190B are created in the bearer information 195. The IP address of the S-GW 52 is assigned to the entry 190A, and the IP address of the S-GW 42 is assigned to the entry 190B.

  Conventionally, since voice data or the like is transferred via the P-GW 21, the intra-P-GW bearer ID 195B is always set information. However, in the second embodiment, audio data or the like is transferred without going through the P-GW 21 by a process described later.

  With reference to FIG. 10, the bearer information table 200 when the P-GW 21 performs a loopback determination between a plurality of S-GWs (described later with reference to FIG. 11) will be described. In FIG. 10, the bearer information management table 200 manages information when the P-GW 21 determines to return between a plurality of S-GWs based on the information in the bearer information management table 190 included in the PCRF 12 of FIG. 9. The bearer information is information related to the bearer used for transferring the service flow.

  In FIG. 10, the bearer information management table 200 includes a user ID 201, a user IP 202, a P-GW ID 203, an S-GW ID 204, and bearer information 205. The user ID 201 stores an identifier for uniquely identifying the terminal. “User # 1” is assigned to the user ID 201 of the UE 71 in FIG. On the other hand, “user # 2” is assigned to the user ID 201 of the UE 72.

  The user IP 202 stores the IP address assigned to the terminal. The user IP of the UE 71 in FIG. 8 is assigned “192.168.0.0.100”. On the other hand, the user IP 202 of the UE 72 is assigned “192.168.0.200”.

  The P-GW ID 203 stores an IP address assigned to the P-GW 21 through which voice data is transferred. The S-GW ID 204 stores an IP address assigned to the S-GWs 42 and 52 through which voice data is transferred.

  The bearer information 205 is determined based on route determination information (see FIG. 12). The bearer information 205 stores information on bearers set in the S-GWs 42 and 52 and the P-GW 21. Specifically, the bearer information 205 includes a flow ID 185A, a P-GW bearer ID 205B, and an S-GW bearer ID 205C.

  The flow ID 205A stores an identifier for identifying a flow transferred using the set bearer. The flow ID 205A is the same as the flow ID 152A. The intra-P-GW bearer ID 205B stores an identifier for identifying a bearer set in the P-GW 21. The intra-P-GW bearer ID 205B is an identifier assigned by the P-GW 21. The intra-S-GW bearer ID 205C stores an identifier for identifying a bearer set in the S-GWs 42 and 52. The intra-S-GW bearer ID 205C is an identifier assigned by the P-GW 21.

  In FIG. 10, entries 200 </ b> A to 200 </ b> B are created in the bearer information 205. In the bearer management information 190, the IP address of the P-GW 21 is assigned to both the entry 190A and the entry 190B. The entry 190A is assigned the S-GW 52 IP address, and the entry 190B is assigned the IP address of the S-GW 42. For this reason, the intra-P-GW bearer ID 205B of the bearer information 205 sets “−” as the identifier for identifying the bearer set in the P-GW 21. On the other hand, for the intra-S-GW bearer ID 185C, the entry 180A has an intra-S-GW bearer ID “5101” including “user # 2 (UE 72)” of the user ID 181 of the communication partner and the intra-S-GW bearer ID “5201”. Is set. In addition, in the entry 180B, an intra-S-GW bearer ID “5201” including “user # 1 (UE 71)” of the user ID 181 of the communication partner and the intra-S-GW bearer ID “5101” is set. Note that when “-” is set in the identifier of the intra-P-GW bearer ID 185B, no bearer is added to the P-GW.

  With reference to FIG. 11, the flow of the route determination of the P-GW 21 will be described. In FIG. 11, this flow is started when waiting for an additional bearer setting request from the PCRF. Note that steps 111 to 116 in FIG. 11 are the same as steps 101 to 106 in FIG. One difference is that whether or not two UEs are accommodated in the same S-GW (S104, S114), route optimization is not performed (S104), or loopback between multiple S-GWs is performed. Is determined (S114).

With reference to FIG. 12, the session establishment call flow when UE 71 and UE 72 are accommodated in different S-GWs will be described.
In FIG. 12A, first, the UE 71 is connected to the P-GW 21 via the eNB 53A, the MME 51, and the S-GW 52, and is in a state where a general-purpose bearer is established. Moreover, UE72 is connected to P-GW21 via eNB43A, MME41, and S-GW42, and is in the state which established the general-purpose bearer. At this time, the IP address “192.168.0.0.100” is assigned to the UE 71. On the other hand, the IP address “192.168.0.200” is assigned to the UE 72. Further, the bearer information management table 190 managed by the PCRF 12 is in a state in which entries 190A and 190C related to the general-purpose bearer are set.

  The UE 71 and the UE 72 negotiate a call session using SIP (S451). The CSCF 11 extracts service information (communication IP address of voice traffic, port number, media type, used bandwidth, etc.) from the SIP message transmitted / received between the UE 71 and the UE 72, and transmits the extracted service information to the PCRF 12. (S452). The PCRF 12 sets the transmitted information in the service information management table 150, and returns an ACK to the CSCF 11 (S453). 150A and 150B in FIG. 3 show settings when UE 71 and UE 72 negotiate bidirectional voice communication.

  Next, the PCRF 12 determines a policy relating to bearer establishment based on the transmitted service information (S454). The PCRF 12 that has determined the policy regarding the bearer establishment transmits an additional bearer setting request to the P-GW 21 (S456). The additional bearer setting request includes a user ID 171, a flow filter 152B, and QoS / billing information. The dedicated bearer setting request includes other information.

  The P-GW 21 that has received the additional bearer setting request performs route determination based on information included in the received additional bearer setting request (S457). After the route determination, the P-GW 21 transmits a multiple S-GW return bearer setting request to the S-GW 52 (S458). The multiple S-GW loopback bearer setting request includes a bearer information table 190 and QoS / billing information. The multiple S-GW loopback bearer setting request includes other information.

  The S-GW 52 that has received the multiple S-GW loopback bearer setting request transmits a bearer establishment request to the MME 51 based on the information included in the received S-GW loopback bearer setting request, and between the UE 71 and the eNB 53A, And an additional bearer is established between eNB53A and S-GW52 (S459).

  After the additional bearer is established in step 459, the S-GW 52 returns a multiple S-GW return bearer setting response to the P-GW 21 (S461). The P-GW 21 that has received the S-GW return bearer setting response returns an additional bearer setting response to the PCRF 12 (S462).

  In FIG. 12B, next, the PCRF 12 transmits an additional bearer setting request to the P-GW 21 (S463). The P-GW 21 that has received the additional bearer setting request transmits a multiple S-GW return bearer setting request to the S-GW 42 that accommodates the UE 72 (S464).

  In steps 464 to 467, the same processing as in steps 458 to 461 is performed between the P-GW 21 and the S-GW 42, between the S-GW 42 and the MME 41, between the MME 41 and the eNB 43A, and between the eNB 43A and the UE 72. That is, in step 464, the S-GW 42 that has received the multiple S-GW loopback bearer setting request establishes a bearer to the MME 41 in step 466 based on the information included in the received multiple S-GW loopback bearer setting request. A request is transmitted, and additional bearers are established between the UE 72 and the eNB 43A and between the eNB 43A and the S-GW 42. In step 467, the S-GW 42 returns a response between multiple S-GW return bearers to the P-GW 21.

  The P-GW 21 that has received the multiple S-GW loopback bearer setting response returns an additional bearer setting response to the PCRF 12 (S468). Next, the PCRF 12 transmits an inter-bearer link creation request to the P-GW 21 (S469). In the inter-bearer link creation request, link source bearer information (information related to the bearer used for the UE 71 to transmit and receive voice data) and link destination bearer information (information related to the bearer used for the UE 72 to transmit and receive voice data) and It is included.

  The P-GW 21 that has received the inter-bearer link creation request transmits the inter-bearer link creation request to the S-GW 52 (S462).

  Next, the S-GW 52 that has received the inter-bearer link creation request transmits the received inter-bearer link creation request to the S-GW 42 (S471).

  Moving to FIG. 12C, in step 471, the S-GW 42 that has received the inter-bearer link creation request creates link information between the bearers based on the information included in the received inter-bearer link creation request (S501). The S-GW 42 that has created the link between the bearers transmits a link creation notification to the MME 41 (S502). The link creation notification to be transmitted includes link information. The MME 41 that has received the link creation notification stores the link information included in the link creation notification and returns an ACK to the S-GW 42 (S503).

  Next, the S-GW 42 transmits a bearer link creation response to the S-GW 52 (S504). In step 469, the S-GW 52 that has received the bearer link creation response from the S-GW 42 creates link information between the bearers based on the information included in the bearer link creation request received from the P-GW 21 (S506). The S-GW 52 that has created the inter-bearer link transmits a link creation notification to the MME 51 (S507). The link creation notification to be transmitted includes link information. The MME 51 that has received the link creation notification stores the link information included in the link creation notification and returns an ACK to the S-GW 52 (S508).

  Next, the S-GW 52 transmits a bearer link creation response to the P-GW 21 (S509). The P-GW 21 that has received the bearer link creation response transmits a bearer link creation response to the PCRF 12 (S511). The PCRF 12 that has received the bearer link creation response transmits a bearer setting completion notification to the CSCF 11 (S512). The CSCF 11 that has received the bearer setting completion notification returns an ACK to the PCRF 12 (S513). UE71 and UE72 complete the SIP session establishment between them (S514).

  Thereafter, voice communication between the UE 71 and the UE 72 is started, and the voice traffic is transferred through a route of [UE71-eNB53A-SGW52-SGW42-eNB43A-UE72].

  In the conventional communication system, the voice traffic is transferred through the route [MN71-eNB53A-SGW52-SGW42-eNB43A-CN72] by the QoS determination routine of the PCRF 12, but in this embodiment, the route determination is performed by the P-GW21. There is a feature.

  According to the present embodiment, the shortest data path can be set without increasing the load on the policy server and without depending on PMIPv6.

  DESCRIPTION OF SYMBOLS 1 ... PDN network, 2 ... IMS network, 3 ... LTE core network, 11 ... Call control server (CSCF), 12 ... Policy server (PCRF), 21 ... P-GW, 22 ... HSS, 41 ... MME, 42 ... S -GW, 43 (A to C) ... eNB, 51 ... MME, 52 ... S-GW, 53 (A to C) ... eNB, 71 ... UE, 72 ... UE, 150 ... Service information management table, 170 ... bearer information Management table (PCRF, same S-GW loopback), 180 ... Bearer information management table (P-GW, same S-GW loopback), 190 ... Bearer information management table (PCRF, loopback between different S-GWs) ), 200... Bearer information management table (P-GW, when returning between different S-GWs).

Claims (7)

In a communication system comprising a mobility anchor that connects a terminal to a packet data network, an access gateway device that connects the terminal to the mobility anchor, and a policy server that controls the mobility anchor and the access gateway device,
The access gateway device includes a first access gateway device,
A first communication path is set between the first terminal and the first access gateway apparatus, a second communication path is set between the first access gateway apparatus and the mobility anchor, A third communication path is set between the second terminal and the first access gateway apparatus, and a fourth communication path is set between the first access gateway apparatus and the mobility anchor,
The first terminal communicates with the second terminal via the first communication path, the second communication path, the fourth communication path, and the third communication path;
The mobility anchor manages communication path management information including information on the communication path of each terminal,
The policy server transmits an additional bearer setting request for associating the communication path of the first terminal and the communication path of the second terminal to the mobility anchor,
When the mobility anchor receives the additional bearer setting request, the mobility anchor sets the fifth communication path connected to the first communication path and the third communication path by analyzing the content of the additional bearer setting request. Information about the fifth communication path is recorded in the communication path management information, and the communication path management is performed to the first access gateway device. Send a link creation request with information,
The first access gateway device transmits data transmitted from the first terminal via the first communication path based on the communication path management information to the fifth communication path and the first communication path. 3. A communication system, characterized by transmitting to the second terminal via 3 communication paths. The access gateway device further includes a second access gateway device,
When the first terminal and the second terminal pass through the same mobility anchor and the different access gateway device, and the first terminal passes through the second access gateway device, A sixth communication path is set between the first terminal and the second access gateway apparatus, a seventh communication path is set between the second access gateway apparatus and the mobility anchor, and The third communication path is set between the second terminal and the first access gateway apparatus, and the fourth communication path is set between the first access gateway apparatus and the mobility anchor. Set,
The first terminal communicates with the second terminal via the sixth communication path, the seventh communication path, the fourth communication path, and the third communication path;
The mobility anchor manages communication path management information including information on the communication path of each terminal,
The policy server transmits an additional bearer setting request for associating the communication path of the first terminal and the communication path of the second terminal to the mobility anchor,
When the mobility anchor receives the additional bearer setting request, the mobility anchor analyzes the contents of the additional bearer setting request to thereby connect the eighth communication path connected to the third communication path and the sixth communication path. It is determined whether or not it is possible to set between one access gateway device and the second access gateway device, and whether or not it is possible to set the eighth communication channel is determined as information on the eighth communication channel in the communication Record in the route management information, send a link creation request including the communication route management information to the access gateway device,
The access gateway device transmits the data transmitted from the first terminal via the sixth communication path, based on the communication path management information, to the seventh communication path and the third communication path. 2. The communication system according to claim 1, wherein the communication system transmits data to the second terminal via a network. A mobility anchor in a communication system comprising a mobility anchor that connects a terminal to a packet data network, an access gateway device that connects the terminal to the mobility anchor, and a policy server that controls the mobility anchor and the access gateway device. ,
The access gateway device includes a first access gateway device,
A first communication path is set between the first terminal and the first access gateway apparatus; a second communication path is set between the first access gateway apparatus and the mobility anchor; and A third communication path is set between the second terminal and the first access gateway apparatus, and a fourth communication path is set between the first access gateway apparatus and the mobility anchor,
The first terminal communicates with the second terminal via the first communication path, the second communication path, the fourth communication path, and the third communication path;
The mobility anchor manages communication path management information including information on the communication path of each terminal,
The policy server transmits an additional bearer setting request for associating the first communication path and the third communication path to the mobility anchor,
When the mobility anchor receives the additional bearer setting request, the mobility anchor sets the fifth communication path that connects the first communication path and the third communication path by analyzing the content of the additional bearer setting request. Information on the fifth communication path is recorded in the communication path management information, and the communication path management information is included in the access gateway device. A mobility anchor characterized by transmitting a link creation request. The mobility anchor according to claim 3, wherein
In the route determination, when the first terminal and the second terminal pass through the same access gateway device as the same mobility anchor, the route determination determines the fifth communication path in the access gateway device. A mobility anchor characterized by setting. The access gateway device further includes a second access gateway device,
When the first terminal and the second terminal pass through the same mobility anchor and the different access gateway device, and the first terminal passes through the second access gateway device,
A sixth communication path is set between the terminal 1 and the second access gateway apparatus; a seventh communication path is set between the second access gateway apparatus and the mobility anchor;
The first terminal communicates with the second terminal via the sixth communication path, the seventh communication path, the fourth communication path, and the third communication path;
The mobility anchor manages communication path management information including information on the communication path of each terminal,
The policy server sends an additional bearer request for associating the sixth communication path and the communication path of the third terminal to the mobility anchor;
When the mobility anchor receives the additional bearer setting request, the mobility anchor analyzes the content of the additional bearer setting request to set the eighth communication path connecting the sixth communication path and the third communication path to the first communication path. It is determined whether or not it is possible to set between one access gateway device and the second access gateway device, and whether or not it is possible to set the eighth communication channel is determined as information on the eighth communication channel in the communication The mobility anchor according to claim 3, wherein the mobility anchor is recorded in path management information and transmits a link creation request including the communication path management information to the access gateway apparatus. The mobility anchor according to claim 3, wherein
In the route determination, when the first terminal and the second terminal pass through the access gateway device different from the same mobility anchor, an eighth communication path is set in the access gateway device by the route determination. A mobility anchor characterized by The mobility anchor according to claim 3, wherein
The mobility anchor, wherein the route determination is performed when the additional bearer setting request is received.

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